1. Field of the Invention
The present invention relates to a semiconductor device and method of manufacturing the same. More particularly, the present invention relates to a semiconductor device and method of manufacturing the same that can prevent repair failure.
2. Description of the Related Art
A semiconductor device is manufactured by executing a fabrication (“FAB”) process, in which integrated circuits comprised of cells are formed on a wafer using pre-defined circuit patterns, and an assembly process, in which the wafer is packaged in units of a chip.
Electrical Die Sorting (EDS), which is used to inspect electrical characteristics, is performed between the fabrication process and the assembly process.
Defective cells are sorted by inspecting their electrical characteristics. Sorted defective cells are replaced with redundant cells, which are already made, by performing a repair process, so the chip can operate normally. Therefore, semiconductor device yields can be improved.
The repair process is performed by cutting a wiring region connected to the defective cell with a laser beam. The wire cut by the laser beam is called a fuse, and a region in which fuses are closely packed is called a fuse region.
The fuse region is formed while word lines and bit lines of semiconductor device cells are formed. If fuses are formed at word lines or bit lines that are located at a lower region of a semiconductor device due to increasing integration of semiconductor devices, etching depth is increased during the fuse opening process. Thus, a metal interconnection or a conductive layer of a capacitor electrode located at an upper region is used as the fuse.
If the pitch of fuses is increased in order to prevent bridging from occurring between the fuses, the area of the fuse region is increased. On the other hand, if the pitch of fuses is decreased, an adjacent fuse can be damaged during fuse cutting, and bridging can occur between adjacent fuses due to fuse residue after fuse cutting. Due to the ever increasing integration of semiconductor memory devices, fuse problems are a continuing concern. Thus, repair failure is increased, and semiconductor device reliability is decreased.